Multifunctional Nanoparticles for Targeted Imaging and Therapy of Cancer
- PDF / 3,672,067 Bytes
- 12 Pages / 612 x 792 pts (letter) Page_size
- 80 Downloads / 218 Views
1257-O07-02
Multifunctional Nanoparticles for Targeted Imaging and Therapy of Cancer Yong-Eun Koo Lee1 and Raoul Kopelman1 1 Chemistry Department, The University of Michigan, 930 N. University Avenue, Ann Arbor, MI 48109-1055, U.S.A. ABSTRACT The idea of making biocompatible multifunctional nanoparticles, combining therapy, imaging and targeting, was aimed at cancer from the start a dozen years ago. This presentation will emphasize targeted theranostic nanoparticles, where “theranostic” literally means combining therapy and diagnostics, but more generally may mean a combination of imaging/visualization with therapy/surgery. Specific examples will cover (1) imaging (MRI, CT and optical methods), (2) therapy (chemo, photodynamic, radiation) and (3) guided surgery (using intra-operative imaging and therapy). Progress on brain and on head and neck cancer will be reported. INTRODUCTION Cancer is the second most common cause of death in the US, accounting for nearly 1 of every 4 deaths [1]. Yet, diagnosis and treatment of cancer remains a challenge due to limitations of the modalities. To date, modern imaging techniques such as CT, PET, ultrasound and MRI are rapidly emerging standards for the detection of cancers. However, these imaging scans are neither sensitive enough to replace biopsy nor are they yet able to find out invisible cancer cells at early stages of the disease. Cancer treatment modalities include surgery and non-surgical therapy, such as radiation therapy, chemotherapy and photodynamic therapy (PDT). Surgery is the oldest but still the primary cancer treatment. It is invasive and often not efficient due to incomplete resection, as neoplastic tissue is virtually indistinguishable from normal tissue and due to the location of tumor. Non-surgical therapy causes collateral organ damage, leading to many side effects, because of its non-selectivity. Moreover, tumor cells are sometimes resistant to the therapy. Over the decade, nanoparticles have emerged as a prominent platform for tumor-selective delivery with reduced systemic exposure of the drugs and contrast agents, so as to overcome the problems of current imaging and therapeutic strategies [2]. Such successes have been enabled by nanoparticles’ size, versatile engineerability as well as non-toxicity. The nanoparticles can be engineered to carry high payloads of drugs and/or contrast agents, offering a coherent, critical mass of destructive power for intervention. The nanoparticles may accumulate selectively in tumors through passive targeting because of the “enhanced permeability and retention effect” (EPR effect) [3], in which leaky neovasculature and lack of lymphatic drainage of tumor lead to macromolecular accumulation. It is also possible to enhance tumor accumulation of the nanoparticles by active molecular targeting—the surface coupling of tumor-specific targeting moieties that can bind selectively to either uniquely expressed or overexpressed molecules in tumor compared to normal tissues. The nanoparticles can be surface-engineered with polyethylen
Data Loading...
